1. Field of the Invention
The present invention relates to a haptic-sense-generation input device that is particularly suitable for use in vehicles.
2. Description of the Related Art
FIG. 8 shows a conventional haptic-sense-generation input device in which the main part is shown in cross section. FIG. 9 is a sectional view taken along line 9xe2x80x949 in FIG. 8.
A body 51 is a generally rectangular parallelepiped box made of a synthetic resin and is formed by molding. The body 51 is composed of a circumferential side wall 51a, a top wall 51b that is provided above the side wall 51a, a circular opening 51c that is formed in the top wall 51b, a first holding portion 51d that projects inward from the top wall 51b, a bottom wall 51e that is provided below the side wall 51a, and a generally cylindrical second holding portion 51f that extends inward from the bottom wall 51e. 
The opening 51c and the second holding portion 51f are opposed to each other. The body 51 has a relatively large volume.
A motor 52 has a generally cylindrical base portion 52a and a motor shaft 52b that projects from the base portion 52a. The motor 52 is provided in such a manner that a rear portion of the base portion 52a is housed in and held by the second holding portion 51f and the motor shaft 52b projects outward through the opening 51c. The motor 52 is of a large size because it is required to generate a prescribed, relatively high torque.
A manipulation knob 53 is made of a synthetic resin and is formed by molding. The manipulation knob 53 is composed of a generally cylindrical manipulating portion 53a, a cylindrical fixing portion 53b that is provided inside the manipulating portion 53a and projects from the center of the manipulating portion 53a, an annular brim 53c that extends outward from the bottom of the manipulating portion 53a perpendicularly to the axis of the fixing portion 53b, and a cylindrical first pulley 53d that extends from a radial position, close to its outer periphery, of the brim 53c so as to be concentric with the fixing portion 53b. 
The motor shaft 52b of the motor 52 is directly inserted in the cylindrical fixing portion 53b of the manipulation knob 53, and the motor shaft 52b is fixed to the fixing portion 53b by press fitting or screwing, for example.
When the manipulation knob 53 is attached, the manipulating portion 53a and the brim 53c are located outside the body 51 and the first pulley 53d is located inside the body 51.
A coding member 54 is composed of a disc-shaped rotator 54a, a support shaft 54b that penetrates through the center of the rotator 54a and extends in the vertical direction that is perpendicular to the rotator 54a, a plurality of slits 54c that are formed in the rotator 54a so as to be arranged concentrically with the support shaft 54b, and a disc-shaped second pulley 54d that expends from a prescribed position of the support shaft 54b parallel with the rotator 54a. 
One end portion of the support shaft 54b of the coding member 54 is rotatably attached to the first holding portion 51d of the body 51, whereby the rotator 54a can rotate. In this state, the support shaft 54b of the coding member 54 is parallel with the motor shaft 52b of the motor 52 and the second pulley 54d of the coding member 54 is flush with the first pulley 53d of the manipulation knob 53.
A photointerrupter 56 has a light-emitting element 56a and a photodetector 56b, and has a function that light that is emitted by the light-emitting element 56a is detected by the photodetector 56b. The photointerrupter 56 is provided in such a manner that the rotator 54a having the slits 54c is interposed between the light-emitting element 56a and the photodetector 56b. As the rotator 54a rotates, the photodetector 56a intermittently detects light that is emitted by the light-emitting element 56a. 
That is, the photointerrupter 56 and the coding member 54 constitute a rotation detecting means for detecting a rotation angle of the manipulation knob 53.
A belt 55 is made of elastic rubber or a metal and has a ring shape. The belt 55 is wound on the first pulley 53d and the second pulley 54d, whereby the first pulley 53d and the second pulley 54d rotate in link with each other. That is, the belt 55 causes the motor shaft 53b of the motor 52 and the rotator 54a of the coding member 54 to rotate in link with each other.
A push-button switch 57 is composed of a base portion 57a and a push button 57b that projects from the base portion 57a. The push-button switch 57 is provided close to the motor 52 at such a position that the push button 57b is opposed to a tip portion of the first pulley 53d of the manipulation knob 53. When the first pulley 53d is manipulated in the axial direction, the push-button switch 57 is pushed (manipulated) by the tip portion of the first pulley 53d. That is, when the manipulation knob 53 is depressed in the axial direction, it is moved in the axial direction together with the motor shaft 52b, whereby the push-button switch 57 is manipulated.
A controller 58, which is a central processing unit (CPU), for example, produces a prescribed output signal when receiving a prescribed input signal. The output signal is used for controlling a haptic sense that is generated by the motor 52.
For example, when a proper output signal is output from the controller 58, the motor shaft 52b of the motor 52 is driven so as to produce a desired haptic sense. The haptic sense that is transmitted to the manipulation knob 53 can be changed depending on how the motor shaft 52b is driven.
Function selection switches 59 are a plurality of push-button switches, for example. A desired function can be selected by manipulating one of the push-button switches.
Output signals of the respective function switches 59 are input to the controller 58. For example, by using the function selection switches 59, selection can be made among such functions as tuning of a radio receiver, song selection of a compact disc (CD) player, and route setting of a navigation system. The function selection switches 59 are provided at prescribed locations.
The motor 52 generates a prescribed haptic sense based on an output signal of each of the function selection switches 59.
A monitor 60 is a liquid crystal display device, for example, and has a display screen. The monitor 60 is provided at a prescribed location and performs display that relates to a desired function based on a control signal for the desired function that is supplied from the controller 58.
Next, the operation of the above-configured conventional haptic-sense-generation input device will be described. A control signal for generating a haptic sense corresponding to a function that has been selected by manipulating one of the function selection switches 59 is input to the motor 52. Based on the control signal, the motor 52 generates a prescribed haptic sense, which is transmitted to the manipulation knob 53 that is directly attached to the motor shaft 52b of the motor 52.
A more specific operation of the conventional haptic-sense-generation input device that is performed in tuning in to a radio broadcast will be described below. First, one of the function selection switches 59 that is provided for a function of tuning in to a radio broadcast is manipulated.
In response, the controller 58 inputs, to the motor 52, a control signal for generating a haptic sense that corresponds to the function of tuning in to a radio broadcast. Based on the control signal, the motor 52 generates a prescribed haptic sense that corresponds to the function of tuning in to a radio broadcast.
Then, when the manipulation knob 53 is manipulated, the haptic sense is transmitted to the manipulation knob 53 that is directly attached to the motor shaft 52b of the motor 52 and the names of broadcasting station to tune in to such as NHK first, NHK second, TBS, and Nippon Broadcasting System are displayed on the monitor 60.
Then, the manipulation knob 53 is rotated clockwise or counterclockwise so as to tune in to one of the above broadcasting stations. While the manipulation knob 53 is rotated, a rotation angle of the manipulation knob 53 is detected by the rotation detecting means that is composed of the photointerrupter 56 and the coding member 54, whereby the radio receiver can be tuned to the desired broadcasting station.
However, in the conventional haptic-sense-generation input device, the manipulation knob 53 is directly attached to the motor shaft 52b of the motor 52 and a haptic sense that is generated by the motor 52 is transmitted to the manipulation knob 53 directly.
Nowadays, haptic-sense-generation input devices capable of generating strong haptic senses are desired. To satisfy this requirement, it is necessary to use a large-sized motor 52 capable of producing high torque. This results in problems that the large-sized motor 52 is costly and makes the haptic-sense-generation input device larger and heavier.
The present invention has been made to solve the above circumstances, and an object of the invention is therefore to provide a haptic-sense-generation input device that is reduced in size and weight.
A haptic-sense-generation input device according to the invention comprises a manipulation knob; a shaft that holds the manipulation knob and is held rotatably by a bearing; a motor having a motor shaft that is parallel with the shaft; rotation detecting means for detecting a rotation angle of the manipulation knob; a first gear that is attached to the shaft so as to be rotated by the manipulation knob; and a second gear that is attached to the motor shaft and is rotated by the first gear, wherein a haptic sense that is generated by the motor is transmitted to the manipulation knob via the first gear and the second gear.
With this configuration, the motor can be reduced in size and weight as well as in cost while strong haptic senses can be obtained. Further, the haptic-sense-generation input device as a whole can be reduced in size and weight.
In the haptic-sense-generation input device according to the invention, the rotation detecting means comprises a rotator and a rotatable support shaft that holds the rotator and is parallel with the shaft and the motor shaft, and a third gear that is rotated by the first gear to manipulate the rotation detecting means is further provided.
With this configuration, since the third gear is rotated by the first gear, a slip is less likely to occur that in the conventional device in which the rotation detecting means uses a belt; the gear rotation is made reliable and stable.
In the haptic-sense-generation input device according to the invention, the first gear is an internal gear and the second gear and the third gear are engaged with the internal gear.
With this configuration, since the second and third gears having prescribed gear ratios with respect to the first gear are rotated by the first gear, the gear rotation is made stable while the haptic-sense-generation input device is reduced in size.
In the haptic-sense-generation input device according to the invention, the manipulation knob is formed with the first gear that is the internal gear.
With this configuration, the first gear can be formed easily and the cost of the haptic-sense-generation input device can be reduced accordingly.
The haptic-sense-generation input device according to the invention further comprises a fourth gear that is engaged with the internal gear.
With this configuration, since the internal gear is engaged with the second, third, and fourth gears, the internal gear is pulled toward the fourth gear by the fourth gear itself. Therefore, the second and third gears rotate being engaged with the internal gear reliably and hence the internal gear can rotate stably.
In the haptic-sense-generation input device according to the invention, the second gear, the third gear, and the fourth gear are located at the respective apices of an equilateral triangle.
With this configuration, the rotation of the internal gear is made more stable.
In the haptic-sense-generation input device according to the invention, the shaft is movable in an axial direction thereof, and a push-button switch that is manipulated when the shaft is moved in the axial direction and a printed wiring board that is mounted with the push-button switch are further provided.
With this configuration, the push-button switch can be manipulated stably and attached easily while the cost of the haptic-sense-generation input device is reduced.
The haptic-sense-generation input device according to the invention further comprises an illumination lamp mounted on a printed wiring board, for illuminating the manipulation knob.
With this configuration, the manipulation knob can be illuminated by the illumination lamp and the illumination lamp can be attached easily while the cost of the haptic-sense-generation input device is reduced.
In the haptic-sense-generation input device according to the invention, the printed wiring board is a single printed wiring board that is mounted with the push-button switch, the illumination lamp, and the rotation detecting means.
With this configuration, since the above components are mounted on the single printed wiring board, they can be attached easily while the cost of the haptic-sense-generation input device is reduced.
In the haptic-sense-generation input device according to the invention, the rotation detecting means is a light transmission type encoder.
With this configuration, the transmission type encoder having a simple structure can be attached easily while the cost of the haptic-sense-generation input device is reduced.